In many parts of the United States and other countries very large herbicide or insecticide sprayers are used to cover large acreage plots in the minimum time with minimum labor. Double boom sprayers with each boom 40 to 60 foot in length are not uncommon and multiple boom sprayers are coming into use. Normally there will be an automatic flow control to control flow to the booms with flow being consistent with spray nozzle size and pattern. A problem arises when these large units approach the end of rows or crop being treated if the rows are not equal length.
With normal control systems and with units traveling at 5-15 feet per second an operator either must turn off the sprays prematurely and leave some vegetation untreated or double treat other areas. This results in excess herbicide or insecticide being used to give both increased costs and increased environmental problems.
This invention is aimed at controls for multiple segment boom sprayer units to allow an operator to selectively, in effect, shorten a boom, while spraying, by operating valves in the lines from a header to segments of the multiple boom while instantly recycling an amount of liquid being sprayed that would have gone to the segment of the boom that was turned off or temporarily removed from service. Almost all control systems require a significant time to "line out" to exactly adjust a flow control. In the system of this invention the normal flow control system is upset very little by removing a portion of the spray boom or a segment of multiple booms from service. This is made possible using a plurality of quick opening valves headered to-gether with the header connecting into the flow between the flow control valve and the normal flow control meter and acting to recycle measured amounts of the flow. With each of the quick opening valves followed by a manually adjustable flow valve that is adjusted to allow passage of approximately the amount of flow that is going to the segment of the boom that is turned off and with all manually adjustable valves left in an open position and with exit from the manually adjustable valves recycling to the feed tank, segments of a boom may be instantly turned off and with the associated quick opening valves instantly opened there is instantly almost the exact proper flow going to the sprays. This is possible using automatic quick opening valves such as a solenoid or air operated valves to valve off flow to a boom segment and simultaneously open the proper quick opening valve ahead of the proper hand adjusted valve to allow recycle of very close to the same amount that is not put out to the closed off segment. With simple circuitry almost the proper recycle adjustment and therefore almost the proper amount fed to each segment of the multiple segment boom may occur in a fraction of a second. This is necessary in order that vehicle travel during the adjustment period does not leave some vegetation that is not properly treated. A controller senses the shut off of valves to segments of the boom and make the small adjustment necessary to get exactly the correct quantity through a totalizing flowmeter. The totalizing flowmeter along with input to a computer controller to indicate acreage allows an operator to read and adjust to get exact quantity sprayed on per acre.
It is understood that minor mechanical changes to the invention as outlined may be made by one of normal skill in the art therefore we wish only to be limited to the general spirit and purpose as outlined in these claims and specifications rather than to exact details.